Feed apparatus of tube cold rolling mill

ABSTRACT

A feed apparatus has means for conversion of a uniform rotational motion into an intermittent forward movement whose input shaft is imparted a uniform rotational motion by a drive kinematically connected to the drive of a roll stand, and a feed device being imparted an intermittent forward motion by said conversion means through the output member thereof and transmitting this motion to a tube being rolled. To decrease load on the parts of said conversion means at the moment of feed of the tube being rolled, the feed apparatus is provided with a hydraulic cylinder constantly transmitting, through the piston, fluid pressure onto the feed device in the direction of feed of the tube being rolled thereby making it possible to increase the number of the roll stand double strokes per minute and to roll large-diameter tubes.

United States Patent Grinshpun et a1.

[ 1 Jan. 28, 1975 FEED APPARATUS OF TUBE COLD ROLLING MILL [76] Inventors: Mark lzrailevich Grinshpun, ulitsa Pushkina, 4, kv. 21, Elekstrostal Moskovskoi Oblasti; lgor losifovich Dobkin, ulitsa Zhukovskogo, 8, kv. 25, Krasnogorsk Moskovskoi Oblasti; Gennady Fedorovich Kurenkov, prospekt Lcnina, 30/13, kv. 6, Elektrostal Moskovskoi Oblasti; Alexandr Vasilievich Bushev, ulitsa Mayakorskogo, 3, kv. 66, Khimki Moskovskoi Oblasti, all of USSR.

[22] Filed: Feb. 5, 1974 [21] Appl. No.: 439,829

[52] U.S. Cl 72/252, 72/220, 72/208 [51] int. Cl B2lb 21/04, B2lb 39/06 [58] Field of Search 72/252, 208, 214, 220,

[56] References Cited UNITED STATES PATENTS 2,560,934 7/1951 Coe 72/249 X Coe 72/208 Kaiser 72/189 A feed apparatus has means for conversion of a uniform rotational motion into an intermittent forward movement whose input shaft is imparted a uniform rotational motion by a drive kinematically connected to the drive of a roll stand, and a feed device being imparted an intermittent forward motion by said conversion means through the output member thereof and transmitting this motion to a tube being rolled. To decrease load on the parts of said conversion means at the moment of feed of the tube being rolled, the feed apparatus is provided with a hydraulic cylinder constantly transmitting, through the piston, fluid pressure onto the feed device in the direction of feed of the tube being rolled thereby making it possible to increase the number of the roll stand double strokes per minute and to roll large-diameter tubes.

ABSTRACT 2 Claims, 4 Drawing Figures PATENTEBJANZBISYS SHEET 1 OF 3 FEED APPARATUS or TUBE cou) ROLLING MIL The present invention relates to mechanisms of tube cold rolling mills with a reciprocating roll stand and more particularly to mechanisms for feeding a tube being rolled into a deformation zone ofa tube cold-rolling mill.

An apparatus has previously been proposed for feeding the tube being rolled into the deformation zone of the tube cold rolling mill with a reciprocating roll stand set in motion by a drive, comprising a mechanism for conversion ofa uniform rotational motion into an intermittent forward movement, whose input shaft is continuously rotated from a drive kinematically connected to the roll stand drive and whose output member has an intermittent forward movement strictly constant in magnitude and independent of a load applied thereon, and feed means engaging the tube being rolled, coupled with the output member of said conversion mechanism and being imparted an intermittent forward motion by the latter (See Authors Certificate No. 137,095, the USSR).

The conversion mechanism of the feed apparatus includes a cam shaft which is continuously rotated from a drive kinematically connected to the roll stand drive and a differential bevel gear onto which two motions are transmitted simultaneously: a reverse rotational motion from a cam and a uniform rotational motion imparted by a gear keyed to the cam shaft.

The cam profile is so designed that the cam transmits a rotational motion in one direction onto the differential bevel gear through a rocker arm, the differential gear output shaft turns through a definite angle whereas with the rotational motion transmitted in the other direction, this output shaft does not rotate.

Thus, the differential gear output shaft is imparted an intermittent rotational motion which is then converted into an intermittent forward "movement by means of gear-nuts and screws which constitute an output member of the conversion mechanism and are threaded through said gear-nuts, the screw ends being connected on one side with the feed means enabling the screws to move progressively therewith.

The advantage of this apparatus consists in that, when the cam shaft is imparted a uniform rotational motion from the drive kinematically connected to the roll stand drive, feed of the tube being rolled is effected exactly at the movement required, with the roll stand in a definite position, the amount of feed being strictly determined independent of the roll stand double strokes per minute and the force applied which is most important for obtaining high quality tubing.-

However, in rolling large-dimater tubes the demand for which is consistently growing, the force of stripping the tube off a mandrel at the moment of feed increased due to which it is necessary to enlarge the size of the apparatus parts operating under acceleration or deceleration modes.

Therefore, in case of tube cold rolling mills with an increased number of the roll stand double strokes per minute it is impossible to create a reliably operating feed apparatus for rolling large-diameter tubes since there are quite great inertia forces arising in parts of such an apparatus during, their acceleration or deceleration which results in causing excessive stresses in the apparatus parts and thereby in their failure.

The principle object of the present invention is to provide such a feed apparatus for a tube cold rolling mill which will reliably operate in mills with an increased number of the roll stand double strokes per minute and also in rolling large-diameter tubes.

A feed apparatus is proposed for feeding a tube being rolled into the deformation zone of a tube cold rolling mill with a reciprocating roll stand operated by a drive, comprising means for conversion of a uniform rotational motion into an intermittent forward movement whose input shaft is imparted a uniform rotational motion from a drive kinematically connected to the roll stand drive and whose output member has an intermittent forward motion strictly constant in magnitude and independent of a load applied thereon, and a feed device engaging the tube being rolled and connected to the output member of said conversion mechanism, said member transmitting intermittent forward motion thereto. According to the invention, the apparatus has a hydraulic cylinder continuously transmitting fluid pressure through its movable member onto the feed device in the direction of feed of the tube being rolled, thereby decreasing load on parts of the means for conversion of a uniform rotational. motion into an intermittent forward movement at the moment of feed of the tube being rolled.

a It is preferable, in the feed apparatus, wherein the output member of the means for conversion of a uniform rotational motion into an intermittent forward movement is provided in the form of screws with their ends on one side coupled with the feed device and threaded through rotating nuts located from axial displacement, to make said screws hollow and to place pistons in the screw inner chambers, with their ends being fixedly secured on one side thus forming hydraulic cylinders, the pistons being provided with through passages along their entire length for supplying fluid into the inner chambers of the screws, the fluid pressure being continuously transmitted via the screws onto the feed device thereby decreasing load on the nuts and hence on other parts of the means for conversion of a uniform rotational motion into an intermittent forward movement at the moment of feed of the tube being rolled.

Such design of the feed apparatus simplifies its construction.

As a result, there has been developed a feed apparatus of a tube cold rolling mill reliably operating with a greatly increased number of double strokes per minute and also in rolling large-diameter tubes.

The invention will be hereinafter described taking by way of example an embodiment thereof and with reference to the accompanying drawings in which:

FIG. 1 illustrates a feed apparatus of a tube cold rolling mill made in accordance with the invention with a drive and a stationary frame;

FIG. 2 is a sectional view on the line IIII of FIG. 1; FIG. 3 is a sectional view on the line IIIIlI of FIG. 2;

FIG. 4 is a version of the A assembly of the FIG. 1.

A stationary frame 1 (FIGS. 1, 2, 3) has the form of a closed triangle wherein on support rails 2 (FIG. 2) moves a roll stand 3 (FIGS. 2 and 3) reciprocated by a slider-crank mechanism 4 (FIGS. 2 and 1).

In the roll stand 3, three work rolls 5 (FIG. 2) are arranged, each roll having on one portionof its circumference inserted dies 6 (FIGS. 2, 3) with grooves 7 (FIG. 3) of varying cross-section along the roll circumference which grooves, with the roll stand in a working position approaching the extreme rear one in the rolling direction, form a closed circle corresponding to the diameter of a tube 8 being rolled (FIGS. 1, 2) whereas with the roll stand position approaching the extreme front one they form a closed circle corresponding to the diameter ofa finished tube 9. In order that upon reduction of the tube being rolled the dies can release it with the roll stand in its extreme rear position, the grooves 7 in the dies 6 form a circle of a greater diameter than that of the tube being rolled. With the stand in this extreme rear position, the tube feed is effected in the direction of rolling by a predetermined distance.

The other part of the circumference of the work rolls is supported by back-up rolls 10 (FIG. 2) which, in turn, roll along support plates 11 attached to the rails 2 mounted on mill screws 12 arranged in nuts 13 fastened to the stationary frame 1. The screws have a drive 14 connected therewith via line shafts 15 (FIG. 3).

Bearing supports (not shown) of the work and backup rolls are mounted in a cage 16 (FIGS. 2 and 3) which is linked with connecting rods 17 (FIGS. 1 and 2) of the slider-crank mechanism 4. To impart a synchronous rotational motion to the work rolls, these have pinions (not shown) at their ends, the pinions being in mesh with racks (not shown) fixed on the frame 1.

A crankshaft 18 of the slider-crank mechanism 4 is mounted in bearings (not shown) on a bed plate 19 (FIGS. 2 and 3), whereupon is installed the frame 1, the crankshaft being driven through a reducing gear 20 (FIG. 1) and couplings 21 and 22 from an electric motor 23.

The same electric motor 23, acting through the reducing gears 20, 21 and couplings 25, 26 and 27, transmits a continuous uniform rotational motion to a driven cam shaft 28 (the input shaft of the means for conversion of a rotational motion into an intermittent forward movement) (FIG. 1) of a feed apparatus 29 which uses a feed device 30 (FIGS. 1 and 2) to effect stripping of the tube 8 being rolled off a tapered mandrel 31 (FIG. 2) and to feed this tube by a predetermined distance when the roll stand is in its extreme rear position.

During the roll stand travel the mandrel 31, on which the tube 8 is reduced from its initial diameter to that of the finished tube by the dies 6 owing to varying crosssection groves provided therein, is held from longitudinal displacement by a bar 32 (FIGS. 2, 4) being secured to a movable support (not shown) at the end opposite to the mandrel.

Upon matching the tube being rolled with the axis of rolling 0-0, the movable support of the mandrel bar 32 is withdrawn by a chain drive (not shown) together with the bar and the mandrel in the direction opposite to that of rolling.

The feed apparatus 29 comprises means 33 for conversion of a continuous rotational movement into an intermittent forward movement having the cam shaft 28 whereupon are mounted a cam 34, a counter cam 34 and a pinion 36. The cam 34 is followed by a roller 37 fastened to an arm 38a of a double-arm lever 38 whereas the counter cam is followed by a second roller 39 fastened to a second arm 38b of the double-arm lever 38. The profiles of the cam 34 and that of the counter cam are so selected that the rollers 37 and 39 following them do not go out of continuous contact with the surfaces thereof while the lever 38 swings together with a shaft 40 whereon is mounted a planet carrier 41 with rotating thereon planet bevel wheels 42 of a differential bevel gear 43.

Continuous uniform rotation is transmitted from the cam shaft 28 through a pinion 36 and a cluster gear 44 to a bevel gear 45 of the differential gear 43. The profile of the cam 34 is so designed that when the lever 38 swings together with the planet carrier 41 in a direction coinciding with that of rotation of the bevel gear 45 of the differential gear 43, the planet carrier 41 has such a constant speed that the planet bevel wheels 42 rolling ever the bevel gear 45 transmit no motion to an output bevel gear 46 of the differential 43 whereas when the lever 38 swings in the other direction opposite to the direction of rotation of the gear 45, the planet bevel wheels transmit rotation to the output gear 46 of the differential gear 43. Thus, a uniform rotational motion transmitted onto the cam shaft 28 is converted into an intermittent rotational motion imparted to the output bevel gear 46 of the differential gear 43.

Further, the intermittent rotational motion is converted into an intermittent forward movement. by means of screws 47 moving progressively and constituting the output member of the conversion means and also via gear-nuts 48 being imparted an intermittent rotational motion by the bevel gear 46 of the differential gear 43 through a shaft 49, change pinions 50 and 51 serving to vary the amount of feed, a shaft 52. a gear 53, cam gears 54 and 55 which are brought in engagement and disengaged by a power cylinder 56 through a bearing clutch 57. Simultaneously. rotation of the nuts 48 is effected by means of a gear 58, the gear-nuts 48 being in engagement therewith.

The screws 47 are threaded through the gear-nuts 48, the screw ends on one side being connected with the feed device 30, and thus the screws move progressively in the direction of rolling.

Returning of the feed device 30 to its initial position is accomplished at an increased speed. the drive being taken from an individual electric motor 59 via a V-belt drive, a friction clutch-pulley 61 actuated and disengaged by a power cylinder 62 through a bearing clutch 63 and further via a shaft 64, a gear 65, the gear-nuts 48 rotated in the reverse direction, and the screws 47.

The second part of the feed apparatus 29 is the feed device 30 consisting of a housing 66 (FIG. 1) moving on guides (not shown) wherein is arranged a stop or tube clamps (not shown) engaging the tube 8 being rolled. The feed device is imparted an intermittent forward movement by the screws 47 coupled therewith through the housing 66. A hydraulic cylinder 67 is connected by a hydraulic drive 68 with a fluid delivery source (not shown) wherefrom fluid pressure is constantly transmitted via a piston rod 69 onto the feed device over the entire length of its travel in the rolling direction due to which the screws 47, the gear-nuts 48 and all the components of the conversion means 33 are relieved from some portion of the load acting thereupon at the moment of feed as the tube 8 is being stripped off the mandrel 31.

FIG. 4 shows a version of the assembly A (FIG. 1) of the feed apparatus 29 wherein the function of the hydraulic cyclinder 67 is taken up by the screws 47 being the output member of the means 33 for conversion of a uniform rotational motion into an intermittent forward movement, and provided with inner chambers wherein pistons 70 are placed with their ends fastened on one side to a support 71. The pistons 70 have through passages 72 extending along their entire length through which fluid under pressure is constantly'supplied into the chambers of the screws'47 by hydraulic drives 73 from a fluid delivery source (not shown).

The screws 47 are mounted in the gear-nuts 48, their ends being connected on one side to the feed device 30. Since fluid pressure is constantly transmitted through the screws 47 to the feed device, the load on the gearnuts 48 decreases and consequently, there occurs a reduction in the load acting on other parts of the means for conversion of a uniform rotational motion into an intermittent forward movement at the moment of feed of the tube 8 being rolled.

Such design of the feed apparatus simplifies its construction and enables fluid pressure to be transmitted via the screws 47 arranged symmetrically to the axis of rolling 0.

The feed apparatus operates as follows.

The electric motor 23 through the coupling 22, the reducing gear 20 and the couplings 21 actuates the crankshaft 18 of the slider-crank mechanism 4 which, through connecting rods 17, imparts a reciprocating motion to the roll stand 3. Simultaneously, the inserted dies 6 of the work rolls roll over the tube 8 fited on the mandrel 31 and entered into the deformation zone, with their varying cross-section grooves 7 so that, during the stand travel the tube is reduced from its initial diameter to that of the finished tube due to reduction both on its diameter and wall thickness. In this way, the tube being rolled elongates and exits in the form of the finished tube 9 on the side of the slider-crank mechanism 4.

A force arising due to reduction of the tube 8 is transmitted from the work rolls 5 through the back-up rolls 10 to the plates 11 along which the rolls 10 roll. Then, this force is transmitted, through the support rails 2 wherein are secured the plates 11, the mill screws 12, the nuts 13, to the stationary closed-type frame 1.

The outside diameter of the finished tube 9 can be controlled in the process of rolling by means of bringing the work rolls 5 close or apart together with the back-up rolls 10, the plates 11 and the support rails 2 relative to the axis of rolling 00 using the mill screws 12 operated from the drive 14 through the line shafts 15.

The inside diameter of the finished tube is controlled by the movement of the tapered mandrel 31 in the axial direction.

During each double stroke of the roll stand 3, with the stand in its extreme rear position in respect to the direction of rolling, the feed apparatus 29 effects, by means of the feed device 30 engaging the tube 8 via a stop or clamps, stripping of the tube off the tapered mandrel 31, and feeds it by a predetermined distance in the rolling direction] In order that feed of the tube 8 being rolled be regularly effected at the moment required with the roll stand 3 in its extreme rear position, the driven shaft 28 of the feed apparatus 29 is kinematically connected to the roll stand drive so that the electric motor 23 transmits through a reducing gear 20, the couplings 25 and 26, the reducing gear 24 and the coupling 27, such kind of rotation onto the driven shaft 28 that it makes one revolution during the time in the course of which the roll stand makes one double stroke.

The shaft 28 is coupled with the reducing gear 24 through the coupling 27 in such a way that the cam 34 mounted on the shaft 28 swings at the moment of feed in such a direction which coincides with that of rotation of the gear 46 of the differential gear 43 which rotation being transmitted through the shaft 49, change gears 50 and 51, the shaft 52, the gear 53, cam gears 54 and 55 actuated by the cylinder 56 via the clutch 57, to the gear-nuts 48.

The gear-nuts 48, by turning through a definite angle, displace the screws 47 which together with the feed device 30 will advance in the direction of rolling and accomplish feed of the tube 8 being rolled.

During each double stroke of the roll stand 3, one portion of the tube 8 being rolled is fed into the deformation zone.

The feed device 30 moves intermittently until it reaches its extreme front position, in the direction of rolling, specified by the design the tube cold rolling mill.

During the entire travel of the feed device 30 in the direction of rolling, into the hydraulic cylinder 67 (FIG. 1) coupled therewith or the inner chambers of the screws 47 (FIG. 4), fluid is continuously supplied under a predetermined pressure which creates pressure transmitted onto the feed device 30 in the direction of feed of the tube 8 being rolled and also relieves the parts of the feed apparatus 29 from some portion of the load arising when stripping the tube 8 off the mandrel and feeding it in the direction of rolling.

Upon the intermittently moving feed device 30 has reached its extreme from position, the cam gears 54 and 55 are disengaged by the hydraulic cylinder 56, and the feed device 30 stops.

Then, the pressure of the fluid delivered into the hydraulic cylinder 67 or the inner chambers of the screws 47 drops, the friction clutch 61 is switched off by the hydraulic cylinder 62, the feed device is disengaged from the tube 8 being rolled and accelerated in the reverse direction by the electric motor 59 acting through the V-belt drive 60, the friction clutch 61, the shaft 64, the gear 65, the gear-nuts 48 and the screws 47 (FIGS. 1, 4). At the same time, the fluid filling the hydraulic cylinder 67 (FIG. 1) or the screws 47 (FIG. 4) is displaced therefrom by the piston rod 69 moving backward or by the pistons and then drained off.

The electric motor 23 is also switched off, and the roll stand 3, upon making several strokes on the tube 8 without feeding it to facilitate withdrawing the mandrel 31 thereout, also stops. The mandrel 31 together with the bar 32 is retracted by a separate chain drive.

The feed device 30 and the mandrel 31 are retracted by a distance which enables a next tube to be interposed between the tail end face of the tube 8 being in the dies 6 and the feed device 30. Upon loading the next tube to be rolled the mandrel 31 is entered therethrough into the rolled tube being in the dies 6.

The hydraulic cylinder 56 actuates cam gears 54 and 55. The friction clutch 61 is disengaged by the hydraulic cylinder 62.

The hydraulic cylinder 67 (FIG. 1) or the inner chambers of the screws 47 (FIG. 4) are supplied with fluid under pressure via the hydraulic piping 68 or the pistons 70, respectively.

The main drive motor 23 is switched on and the process of rolling begins anew.

After the tube 8 has left the zone of the work rolls and is no longer gripped by the dies 6, it becomes the finished tube 9 and is removed from the axis of rolling 0-0 in any known manner.

The use of a hydraulic cylinder for relieving the parts of the feed apparatus from some portion of loads acting thereupon during the feed of the tube being rolled into the deformation zone, has permitted to make the parts of this apparatus smaller in size and in weight than in case such a decrease in loading is not provided which in turn has made it possible to create a feed apparatus running at a higher speed, employed in tube cold rolling mills with a great number of the roll stand strokes and rolling large-diameter tubing.

What we claim is:

l. A feed apparatus for feeding a tube being rolled into the deformation zone of a tube cold rolling mill with a reciprocating roll stand operated from a drive, comprising: means for conversion of a uniform rotational motion into intermittent forward movement and having an input shaft to which the uniform rotational motion is transmitted by a drive kinematically connected to said drive of the roll stand so that said input shaft makes one revolution during the time in the course of which said roll stand makes one double stroke, and an output member having an intermittent forward motion constant in magnitude and independent of a load applied thereon in the direction of said deformation zone at the end of the backward, to the direction of rolling, travel of said roll stand; a feed device coupled with said output member and being imparted said intermittent forward motion therefrom, said device having means to feed the tube being rolled into the deformation zone; a hydraulic cylinder connected to a fluid delivery source to transmit fluid pressure into said feed device in the direction of said deformation zone and hence to decrease load on the parts of said conversion means at the moment of feed of the tube being rolled.

'2. A feed apparatus as of claim 1 characterized in that said output member of the means for conversion of a uniform rotational motion into an intermittent forward movement is provided in the form of screws threaded through nuts located from axial displacement with their ends on one side being connected to said feed device, said screws being made hollow and their inner chambers accommodating pistons with their ends fixedly secured on one side thus forming hydraulic cylinders, said pistons having along their entire length through passages being connected to the fluid delivery source through which passages fluid is being supplied into said inner chambers of the screws such that the fluid pressure is constantly transmitted through said screws onto said feed device thereby decreasing load on said nuts and hence on other parts of said means for conversion ofa uniform rotational motion into an intermittent forward movement at the moment of feed of the tube being rolled. 

1. A feed apparatus for feeding a tube being rolled into the deformation zone of a tube cold rolling mill with a reciprocating roll stand operated from a drive, comprising: means for conversion of a uniform rotational motion into intermittent forward movement and having an input shaft to which the uniform rotational motion is transmitted by a drive kinematically connected to said drive of the roll stand so that said input shaft makes one revolution during the time in the course of which said roll stand makes one double stroke, and an output member having an intermittent forward motion constant in magnitude and independent of a load applied thereon in the direction of said deformation zone at the end of the backward, to the direction of rolling, travel of said roll stand; a feed device coupled with said output member and being imparted said intermittent forward motion therefrom, said device having means to feed the tube being rolled into the deformation zone; a hydraulic cylinder connected to a fluid delivery source to transmit fluid pressure into said feed device in the direction of said deformation zone and hence to decrease load on the parts of said conversion mEans at the moment of feed of the tube being rolled.
 2. A feed apparatus as of claim 1 characterized in that said output member of the means for conversion of a uniform rotational motion into an intermittent forward movement is provided in the form of screws threaded through nuts located from axial displacement with their ends on one side being connected to said feed device, said screws being made hollow and their inner chambers accommodating pistons with their ends fixedly secured on one side thus forming hydraulic cylinders, said pistons having along their entire length through passages being connected to the fluid delivery source through which passages fluid is being supplied into said inner chambers of the screws such that the fluid pressure is constantly transmitted through said screws onto said feed device thereby decreasing load on said nuts and hence on other parts of said means for conversion of a uniform rotational motion into an intermittent forward movement at the moment of feed of the tube being rolled. 